WO2018135385A1

WO2018135385A1 - Accumulator with internal heat exchanger, and refrigeration cycle device equipped with same

Info

Publication number: WO2018135385A1
Application number: PCT/JP2018/000582
Authority: WO
Inventors: 金子　智
Original assignee: サンデンホールディングス株式会社
Priority date: 2017-01-20
Filing date: 2018-01-12
Publication date: 2018-07-26
Also published as: JP2018115839A; DE112018000460T5; JP6813373B2

Abstract

[Problem] To provide an accumulator equipped with an internal heat exchanger and having a simple configuration, with which leakage of a high-pressure refrigerant can easily be discovered, and to provide a refrigeration cycle device equipped with this accumulator. [Solution] An accumulator that is equipped with an internal heat exchanger and is arranged on the upstream side of a compressor provided in a circulation path for circulating a refrigerant in a refrigeration cycle, and that separates a gas/liquid two-phase refrigerant into a gas and a liquid, said accumulator being equipped with: a gas/liquid separation unit 21 having a double-pipe structure into which a gas/liquid two-phase refrigerant is introduced; and a flat pipe 31 that is wrapped around the periphery of this gas/liquid separation unit, and through which a high-pressure refrigerant passes. An internal heat exchange occurs between the gas/liquid separation unit 21 and the flat pipe 31.

Description

Accumulator with internal heat exchanger and refrigeration cycle provided with the same

The present invention relates to an accumulator with an internal heat exchanger having a heat exchange function and a refrigeration cycle provided with the accumulator.

As this type of accumulator with an internal heat exchanger, for example, an accumulator including an internal heat exchanger for an air conditioning system described in Patent Document 1 has been proposed.
The accumulator described in Patent Document 1 includes a cylindrical housing and an internal heat exchanger accommodated in the housing. The internal heat exchanger includes a cylindrical structure having a diameter smaller than the inner diameter of the housing, a high-pressure line formed on the outside, and a low-pressure line formed on the inside. The liquid container having a smaller diameter is formed inside the cylindrical structure. Is arranged.

Gas-liquid two-phase refrigerant is supplied to the liquid container via a cylindrical element and separated into a gas-phase refrigerant and a liquid-phase refrigerant, and the separated gas-phase refrigerant is moved down a low-pressure line formed in a cylindrical structure. Will be discharged through. In the high-pressure line of the cylindrical structure, the high-pressure refrigerant flows from the lower end side toward the upper end, so that the high-pressure refrigerant and the low-pressure refrigerant perform internal heat exchange in the cylindrical structure.

Japanese Patent No. 5350578

By the way, in the accumulator of patent document 1, the liquid container and the internal heat exchanger are arrange | positioned inside a housing, and a low-pressure refrigerant | coolant performs an internal heat exchange with a high-pressure refrigerant | coolant. For this reason, the internal structure of the housing is complicated, and the high-pressure line is arranged inside the housing, so it is difficult to detect when internal leakage of high-pressure refrigerant occurs, and internal leakage failure during manufacturing There is also a problem that it cannot be discovered.
Therefore, the present invention has been made by paying attention to the problem of the conventional example described in Patent Document 1 described above, and has an internal heat exchanger that can easily detect leakage of high-pressure refrigerant with a simple configuration. It aims at providing an accumulator and a refrigerating cycle provided with the same.

In order to solve the above-described problems, an aspect of the accumulator with an internal heat exchanger according to the present invention is a gas-liquid two-phase refrigerant disposed on the upstream side of a compressor provided in a circulation path for circulating the refrigerant in the refrigeration cycle. A gas-liquid separator having a double-pipe structure into which a gas-liquid two-phase refrigerant is introduced, and a flat tube through which a high-pressure refrigerant wound around the gas-liquid separator passes. The internal heat exchange is performed between the gas-liquid separator and the flat tube.

An aspect of the refrigeration cycle according to the present invention includes a compressor that sucks and compresses refrigerant, a radiator that cools the refrigerant compressed by the compressor, and a decompressor that depressurizes the refrigerant cooled by the radiator. And an evaporator for evaporating the refrigerant decompressed by the decompressor; a gas-liquid two-phase refrigerant flowing out from the evaporator is separated into a gas-phase refrigerant and a liquid-phase refrigerant; An accumulator with an internal heat exchanger as described above, supplying a gas-liquid two-phase refrigerant to the gas-liquid separation part of the accumulator with an internal heat exchanger, supplying the separated gas-phase refrigerant to the compressor, and releasing heat. The high-pressure refrigerant flowing out from the vessel is supplied to the flat tube, and the high-pressure refrigerant discharged from the flat tube is supplied to the decompressor.

According to one aspect of the present invention, the flat tube that allows the high-pressure refrigerant to flow is arranged outside the gas-liquid separator, so that an internal heat exchanger that can easily detect leakage of the high-pressure refrigerant with a simple configuration. An accumulator with an accumulator and a refrigeration cycle including the accumulator can be provided.

It is a whole lineblock diagram showing one embodiment of the refrigerating cycle concerning the present invention. It is a perspective view showing a 1st embodiment of an accumulator with an internal heat exchanger concerning the present invention. It is a top view of the accumulator with an internal heat exchanger which concerns on this invention. FIG. 4 is a sectional view taken along line IV-IV in FIG. 3. It is a front view of the accumulator with an internal heat exchanger concerning the present invention. It is sectional drawing on the VI-VI line of FIG. It is a perspective view which shows a double tube. It is a top view of a double tube. It is a perspective view which shows 2nd Embodiment of the accumulator with an internal heat exchanger which concerns on this invention. It is a top view of a 2nd embodiment. It is sectional drawing on the XI-XI line of FIG. It is sectional drawing on the XII-XII line | wire of FIG. It is a front view of 2nd Embodiment. It is sectional drawing on the XIV-XIV line | wire of FIG.

Next, an embodiment of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic, and the relationship between the thickness and the planar dimensions, the ratio of the thickness of each layer, and the like are different from the actual ones. Therefore, specific thicknesses and dimensions should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

Further, the embodiment described below exemplifies an apparatus and a method for embodying the technical idea of the present invention, and the technical idea of the present invention is the material, shape, structure, The layout is not specified as follows. The technical idea of the present invention can be variously modified within the technical scope defined by the claims described in the claims.

[First Embodiment]
First, a refrigeration cycle representing one embodiment of the present invention will be described with reference to FIG.
As shown in FIG. 1, the refrigeration cycle according to the present invention forms, for example, a vehicle air conditioner. The refrigeration cycle 1 circulates a CO ₂ refrigerant (hereinafter simply referred to as “refrigerant”), which is a natural refrigerant, to air-condition the vehicle interior. The refrigeration cycle 1 is installed from an engine room 3 equipped with an engine 2 to a vehicle compartment 4.

Specifically, the refrigeration cycle 1 includes a compressor 11 driven by the engine 2, a radiator 12, an accumulator 13 with an internal heat exchanger, an expansion valve 14, and an evaporator 15.
The compressor 11 sucks and compresses the gas-phase refrigerant to increase the temperature and pressure, and can be selected from compressors such as a reciprocating compressor, a rotary compressor, and a scroll compressor. The refrigerant compressed by the compressor 11 is supplied to the radiator 12 through the refrigerant pipe RP1.

The radiator 12 cools the refrigerant compressed by the compressor 11 by heat exchange with the outside air. The high-pressure refrigerant cooled by the radiator 12 is supplied to a flat tube 31 (described later) provided in the accumulator 13 with an internal heat exchanger via the refrigerant pipe RP2. The high-pressure refrigerant flowing out of the accumulator 13 with the internal heat exchanger is decompressed by an expansion valve 14 as a decompressor disposed in the refrigerant pipe RP3 and supplied to the evaporator 15 as a low-pressure refrigerant.

The evaporator 15 cools the passenger compartment air by exchanging heat between the refrigerant decompressed by the expansion valve 14 and the passenger compartment air. The gas-liquid two-phase refrigerant flowing out of the evaporator 15 is supplied to the accumulator 13 with an internal heat exchanger via the refrigerant pipe RP4 and separated into the liquid phase refrigerant and the gas phase refrigerant, and the gas phase refrigerant is refrigerant pipe RP5. To be supplied to the compressor 11.
The accumulator 13 with the internal heat exchanger supplies the compressor 11 after exchanging internal heat of the gas-liquid separated low-temperature and low-pressure gas-phase refrigerant with the high-pressure refrigerant supplied from the radiator 12.

As shown in FIGS. 2, 3 and 4, the specific structure of the accumulator 13 with an internal heat exchanger is wound around the gas-liquid separation unit 21 and the outer peripheral surface of the gas-liquid separation unit 21, and the internal heat exchanger is It is comprised with the flat tube 31 to comprise.
As shown in FIG. 4, the gas-liquid separation unit 21 includes, for example, a cylindrical double tube 22 having both ends open, a first cap 23 attached to the upper end of the double tube 22, and the double tube 22. And a second cap 24 attached to the lower end of the first cap.

As shown in FIGS. 4, 6, 7 and 8, the double tube 22 is made of an extruded product obtained by extruding a metal material such as aluminum or aluminum alloy having a high thermal conductivity. A thick outer cylinder 22a and an inner cylinder 22b having a smaller diameter and a smaller thickness than the outer cylinder 22a are provided.
As shown in FIG. 4, the outer cylinder 22a and the inner cylinder 22b are formed long so that the upper ends thereof are flush with each other and the lower ends thereof protrude downward from the outer cylinder 22a. Further, as shown in FIGS. 4, 7, and 8, the outer cylinder 22a and the inner cylinder 22b are connected by a partition wall 22c that extends in the axial direction and is formed at a predetermined interval in the circumferential direction. A space surrounded by the inner peripheral surface of the outer cylinder 22a, the outer peripheral surface of the inner cylinder 22b, and two adjacent partition walls 22c serves as a gas phase refrigerant passage 22d through which the gas phase refrigerant passes. Therefore, a plurality of (for example, 18) gas-phase refrigerant passages 22d are formed in the circumferential direction between the outer cylinder 22a and the inner cylinder 22b.

In addition, a communication groove 22e that connects the inner surface of the inner cylinder 22b and each gas-phase refrigerant passage 22d is formed at the upper end of the inner cylinder 22b.
The first cap 23 is formed of, for example, the same metal material as the double tube 22, and as shown in FIGS. 2 to 4, the disk portion 23a that closes the upper end of the double tube 22, and the disk portion 23a. And a ring-shaped flange portion 23b that extends downward from the outer peripheral surface of the double tube 22 and fits to the outer peripheral surface of the outer tube 22a of the double tube 22. An inflow pipe 23c through which the gas-liquid two-phase refrigerant supplied from the evaporator 15 flows into the inner cylinder 22b of the double pipe 22 is formed through the central portion of the disk portion 23a.

The second cap 24 is formed of, for example, the same metal material as the double tube 22, and as shown in FIGS. 2 and 4, the disk portion 24 a that closes the lower end of the inner tube 22 b of the double tube 22, and this A ring-shaped flange portion 24b that extends upward from the outer peripheral surface of the disc portion 24a and fits to the outer peripheral surface of the outer tube 22a of the double tube 22 is provided.
The second cap 24 has a liquid reservoir 26 for storing the liquid-phase refrigerant and the lubricating oil separated on the lower end side of the inner cylinder 22b by the disk portion 24a closing the lower end of the inner cylinder 22b of the double tube 22. The outer peripheral surface of the inner cylinder 22b, the disc portion 24a and the flange portion 24b form a gas phase refrigerant reservoir 24c for temporarily storing the gas phase refrigerant flowing out from the gas phase refrigerant passage 22d.

A discharge pipe 24d that supplies the gas-phase refrigerant temporarily stored in the gas-phase refrigerant reservoir 24c to the compressor 11 between the outer peripheral surface of the inner tube 22b of the double pipe 22 of the disk portion 24a and the flange 24b. Is formed through. Here, the opening surface of the exhaust pipe 24d to the gas-phase refrigerant reservoir 24c opens to the gas-phase refrigerant reservoir 24c of the exhaust pipe 24d so as to open at a position about half the height of the gas-phase refrigerant reservoir 24c. Projection height is set.

An oil return groove 27 for returning the oil stored in the liquid reservoir 26 to the adjacent gas-phase refrigerant reservoir 24c at a position opposite to the discharge pipe 24d on the lower end surface of the inner tube 22b of the double pipe 22 is provided. Is formed.
The double pipe 22 and the first cap 23 and the second cap 24 may be joined by welding or brazing in the fitted state, and the first cap is formed on the male screw portions formed at both ends of the outer cylinder 22a. The female screw portions formed on the second cap 23 and the second cap 24 may be screwed together.

The flat tube 31 is wound so as to cover the outer peripheral surface exposed from the first cap 23 and the second cap 24 of the double tube 22, as shown in FIGS. The flat tube 31 is made of an extruded product made of a metal material such as aluminum or aluminum alloy having a high thermal conductivity like the double tube 22 or the like. Further, as shown in FIG. 4, a plurality of high-pressure refrigerant passages 31 a are formed in the flat pipe 31 to allow the high-pressure refrigerant to pass therethrough in the axial direction of the double pipe 22. Further, the flat tube 31 is set so that the inner peripheral length is shorter than the outer peripheral length of the outer tube 22a, and as shown in FIGS. 2 and 3, both ends of the flat tube 31 in the circumferential direction of the outer tube 22a. It is connected to the 1st connecting pipe 32 and the 2nd connecting pipe 33 which are arrange | positioned along an outer peripheral surface along the axial direction.

As shown in FIG. 6, the first connecting pipe 32 is formed of a cylindrical body whose upper and lower ends are closed, and as shown in FIG. 5, an inflow port 32a for allowing high-pressure refrigerant to flow is formed on the lower end side. A fitting hole 32b for fitting one end of the flat tube 31 is formed in the left side surface so as to extend in the axial direction. One end of the flat tube 31 is fitted and connected to the fitting hole 32b of the first connection tube 32, and the inside of the first connection tube 32 and each high-pressure refrigerant passage 31a of the flat tube 31 are communicated.

As shown in FIG. 6, the second connecting pipe 33 is formed of a cylindrical body whose upper and lower ends are closed like the first connecting pipe 32, and as shown in FIG. 5, a discharge port 33 a that discharges high-pressure refrigerant at the upper end. A fitting hole 33b for fitting the other end of the flat tube 31 on the right side as viewed in FIG. 6 is formed extending in the axial direction. The other end of the flat tube 31 is fitted and connected to the fitting hole 33b of the second connecting tube 33, and the high pressure refrigerant passage 31a of the flat tube 31 is communicated with the inside of the second connecting tube 33.

And the inflow port 32a of the 1st connection pipe 32 of the accumulator 13 with an internal heat exchanger is connected to refrigerant pipe RP2, and the discharge port 33a of the 2nd connection pipe 33 is connected to the expansion valve 14 via refrigerant pipe RP3. Yes. Further, the inflow pipe 23c of the first cap 23 of the accumulator 13 with the internal heat exchanger is connected to the refrigerant discharge port of the evaporator 15 through the refrigerant pipe RP4, and the discharge pipe 24d of the second cap 24 is connected through the refrigerant pipe RP5. Connected to the compressor 11.

Next, the operation of the first embodiment will be described.
In the refrigeration cycle 1, the gas-phase refrigerant is compressed by the compressor 11 and supplied to the radiator 12 as a high-pressure refrigerant. The high-pressure refrigerant is cooled by heat exchange with the outside air by the radiator 12. In this cooling step, the temperature is lowered while the high-pressure refrigerant changes almost at the same pressure.
The cooled high-pressure refrigerant is supplied to the inlet 32a of the first connection pipe 32 of the accumulator 13 with the internal heat exchanger, and is distributed to the high-pressure refrigerant passages 31a of the flat pipe 31 through the first connection pipe 32 and flows in. The high-pressure refrigerant discharged from the other end of the high-pressure refrigerant passage 31a is collected by the second connection pipe 33 and supplied to the expansion valve 14 from the discharge port 33a.

The refrigerant decompressed and expanded by the expansion valve 14 is supplied to the evaporator 15 to exchange heat with the air in the passenger compartment, and as an air-liquid two-phase refrigerant, an inflow pipe 23c of the first cap 23 of the accumulator 13 with an internal heat exchanger. To be supplied.
In the accumulator 13 with the internal heat exchanger, the gas-liquid two-phase refrigerant flowing from the inflow pipe 23c of the first cap 23 flows into the inner cylinder 22b of the double pipe 22 and is gas-liquid separated, and has the highest specific gravity. Large oil is stored in the lowermost layer in the liquid reservoir portion 26 formed on the lower end side of the inner cylinder 22b, and a separated liquid phase refrigerant having a specific gravity smaller than that of the oil is stored thereon.

The separated gas-phase refrigerant moves to the second cap 24 side through a communication groove 22e formed at the upper end of the inner cylinder 22b and further through a gas-phase refrigerant passage 22d formed between the outer cylinder 22a and the inner cylinder 22b. To do. At this time, the flat tube 31 is wound around the gas-phase refrigerant passage 22d, and the high-temperature refrigerant from the radiator 12 is passed through the high-pressure refrigerant passage 31a of the flat tube 31. Internal heat exchange is performed between the high-pressure refrigerant and the low-temperature and low-pressure gas-phase refrigerant. For this reason, the high-temperature high-pressure refrigerant is cooled, and the low-temperature gas-phase refrigerant is heated. Then, the gas-phase refrigerant whose temperature has been increased by the internal heat exchange returns to the compressor 11 from the gas-phase refrigerant reservoir 24c of the second cap 24 through the discharge pipe 24d while maintaining the gas-phase state.

The oil stored in the liquid reservoir 26 of the accumulator 13 with an internal heat exchanger is returned to the gas-phase refrigerant reservoir 24c through the oil return groove 27 formed at the lower end of the inner cylinder 22b, and the upper surface of the oil is discharged. When the upper surface of the pipe 24d is exceeded, oil is returned to the compressor 11 together with the gas-phase refrigerant.
As described above, according to the first embodiment, the internal heat exchanger is configured by winding the flat tube 31 through which the high-pressure refrigerant flows around the outer periphery of the gas-liquid separator 21 constituting the accumulator 13 with the internal heat exchanger. Therefore, in order to ensure a sufficient liquid storage volume, it is only necessary to increase the outer diameter of the outer tube 22a and the inner tube 22b by increasing the outer shape of the double tube 22 constituting the gas-liquid separation unit 21.

Further, since the flat tube 31 through which the high-pressure refrigerant flows is wound around the outer peripheral side of the gas-liquid separation unit 21, when the high-pressure refrigerant leaks from the flat tube 31, it is easily detected using a CO ₂ sensor. can do. Furthermore, when the CO ₂ sensor cannot be used, the leakage of the high-pressure refrigerant can be easily found by attaching the accumulator 13 with an internal heat exchanger in the liquid and visually confirming the presence or absence of bubbles. Moreover, the leakage of the high-pressure refrigerant at the completion of the production of the accumulator 13 with an internal heat exchanger can be detected in the same manner.

Moreover, in the said 1st Embodiment, the gas-liquid separation part 21 of the accumulator 13 with an internal heat exchanger is divided into the double pipe 22, and the 1st cap 23 and 2nd cap which obstruct | occlude both ends of this double pipe separately. 24, and can be easily configured with a small number of parts. Moreover, since the double tube 22 can be constituted by an extruded product obtained by extruding a metal material having a high thermal conductivity, it can be manufactured easily.

Further, since the opening position of the discharge pipe 24d formed in the second cap 24 is higher than the bottom surface of the gas-phase refrigerant reservoir 24c, the liquid-phase refrigerant flows from the oil return groove 27 formed at the lower end of the inner cylinder 22b. When leaking into the gas-phase refrigerant reservoir 24c, the leaked liquid-phase refrigerant can be accumulated up to the opening position of the discharge pipe 24d, and the liquid-phase refrigerant is prevented from being discharged from the discharge pipe 24d to the compressor 11. can do.

Further, the flat tube 31 is formed with a plurality of high-pressure refrigerant passages 31a that are axially spaced inside, and distributes and supplies the high-pressure refrigerant from the first connecting pipe 32 to each high-pressure refrigerant passage 31a. Since the high-pressure refrigerant in the high-pressure refrigerant passage 31a is collected by the second connecting pipe 33, the high-pressure refrigerant can be made to flow uniformly and the internal heat exchange can be performed efficiently.
In the first embodiment, the case where the flat tube 31 is formed wide so as to cover the exposed portion of the double tube 22 has been described. However, the present invention is not limited to this, and a plurality of flat tubes 31 are provided in the axial direction. The divided flat tubes may be connected in parallel to the first connecting tube 32 and the second connecting tube 33.

Next, a second embodiment of the present invention will be described with reference to FIGS.
In the second embodiment, a plurality of rows of flat tubes are wound around the outer periphery of the double tube, and the flow direction of the high-pressure refrigerant is reversed in each row of the flat tubes.
That is, in the second embodiment, a plurality of accumulators 13 with an internal heat exchanger are provided on the outer peripheral surface exposed from the first cap 23 and the second cap 24 of the double pipe 22, as shown in FIGS. Four rows of

flat tubes

41A, 41B, 41C, and 41D are wound at predetermined intervals in the axial direction of the double tube. In each of these flat tubes 41A to 41D, as shown in FIGS. 11 and 12, a plurality of, for example, seven high-pressure refrigerant passages 41a to 41d are formed in parallel in the width direction that is the axial direction of the double tube 22. Has been.

One end of each of the flat tubes 41A to 41D is connected to the first connecting tube 42, and the other end is connected to the second connecting tube 43.
As shown in FIG. 11, the first connecting pipe 42 is configured by a cylindrical body whose both ends are closed, and in the internal space, a partition plate 44 a is provided at a position corresponding to between the flat tubes 41 </ b> A and 41 </ b> B, A partition plate 44b is provided at a position corresponding to between the

flat tubes

41C and 41D, and three

communication spaces

45a, 45b and 45c are formed. A high-pressure refrigerant inflow port 46a is formed at the lower end side of the communication space 45a, and a high-pressure refrigerant discharge port 46b is formed at the upper end side of the communication space 45c.

As shown in FIG. 12, the second connecting pipe 43 is formed of a cylindrical body whose both ends are closed, like the first connecting pipe 42, and the internal space is partitioned at a position corresponding to between the

flat tubes

41B and 41C. A plate 44c is provided to form two

communication spaces

47a and 47b.
For this reason, the high-pressure refrigerant having a high temperature supplied from the radiator 12 to the inlet 46a is equally distributed to the high-pressure refrigerant passages 41a of the flat pipe 41A in the communication space 45a of the first connection pipe 42. The refrigerant flows in the refrigerant passage 41a toward the communication space 47a of the second connection pipe 43 as indicated by the solid arrow in FIG.

The high-pressure refrigerant that has passed through the high-pressure refrigerant passages 41a of the flat tubes 41A merges on the lower side of the communication space 47a of the second connection tube 43, and enters the high-pressure refrigerant passages 41b of the flat tubes 41B from the upper side of the communication space 47a. As shown by the solid line arrows in FIG. 13, the high-pressure refrigerant passages 41 a are evenly distributed and flow in the opposite direction to the flow in the flat tubes 41 </ b> A toward the communication spaces 45 b of the first connection tubes 42.
The high-pressure refrigerant that has passed through the high-pressure refrigerant passages 41b of the flat tubes 41B merges on the lower side of the communication space 45b of the first connection pipe 42, and enters the high-pressure refrigerant passages 41c of the flat tubes 41C from the upper side of the communication space 45b. As shown by solid arrows in FIG. 13, the high-pressure refrigerant passages 41 a are evenly distributed and flow in the opposite direction to the flow in the flat tube 41 </ b> B toward the communication space 47 b of the second connection tube 43.

The high-pressure refrigerant that has passed through the high-pressure refrigerant passages 31c of the flat tubes 31C merges on the lower side of the communication space 47b of the second connection pipe 43, and enters the high-pressure refrigerant passages 41d of the flat tubes 31D from the upper side of the communication space 47b. Evenly distributed, each high-pressure refrigerant passage 41d flows in a direction opposite to the flow in the flat tube 41C as shown by the solid line arrow in FIG. 13 and travels toward the communication space 45c of the first connection tube 32.
The high-pressure refrigerant that has passed through the high-pressure refrigerant passage 41a of the flat tube 41D joins in the communication space 45c of the first connection pipe 42 and is discharged to the expansion valve 14 from the upper discharge port 46b.

Other configurations have the same configurations as those of the first embodiment described above, and corresponding parts to the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.
Next, the operation of the second embodiment will be described.
Since the configuration of the gas-liquid separation unit 21 is the same as that of the first embodiment described above, the low-pressure gas-liquid two-phase refrigerant flowing from the inflow pipe 23 c of the first cap 23 is contained in the double pipe 22. An oil layer is formed in the lower layer of the liquid reservoir 26 due to the difference in specific gravity introduced into the cylinder 22b, and a liquid refrigerant layer is formed in the upper layer. The separated gas-phase refrigerant flows down through the gas-phase refrigerant passage 22d between the outer cylinder 22a and the inner cylinder 22b, and is discharged to the compressor 11 from the discharge pipe 24d of the second cap 24. The oil in the oil layer collected in the lower layer of the liquid reservoir 26 is joined to the gas-phase refrigerant through the oil return groove 27 and returned to the compressor 11.

At this time, the low-temperature and low-pressure gas-phase refrigerant flowing through the gas-phase refrigerant passage 22d between the outer tube 22a and the inner tube 22b passes through the flat tubes 41A to 41D wound around the outer periphery of the double tube 22. The internal heat exchange with the high pressure refrigerant is high, and the temperature rises.
In the flat tubes 41A to 41D, the high-pressure refrigerant flowing from the inlet 46a of the first connecting pipe 32 flows into the high-pressure refrigerant passage 41a of the lowermost flat pipe 41A toward the second connecting pipe 43, and the high-pressure refrigerant flows on the opposite side. After the refrigerant joins through the communication space 47a of the second connection pipe 43, the refrigerant is evenly distributed to the high-pressure refrigerant passage 41b of the flat pipe 41B and flows in a direction opposite to the flow in the flat pipe 41A.

Thereafter, the high-pressure refrigerant sequentially passes through the communication space 45b of the first connection pipe 42, the high-pressure refrigerant passage 41c of the flat pipe 41C, the communication space 47b of the second connection pipe 43, and the high-pressure refrigerant passage 41d of the flat pipe 41D. It reaches the communication space 45c and is discharged to the expansion valve 14 from the discharge port 46b of the communication space 45c.
As described above, according to the second embodiment, the gas-liquid separation unit 21 has the same configuration as that of the first embodiment described above, and thus the same operational effects as those of the first embodiment can be obtained. .

As for the internal heat exchange function, the plurality of flat tubes 41A to 41D, the first connecting tube 42, and the second connecting tube 43 allow high-pressure refrigerant to continuously reach from the lowermost flat tube 41A to the uppermost flat tube 41D. A typical high-pressure refrigerant passage is formed. For this reason, the total length of the high-pressure refrigerant flow path can be significantly increased by using the circumferential lengths of the flat tubes 41A to 41D as compared with the first embodiment described above, which is efficient. Internal heat exchange can be performed.

Here, the high-pressure refrigerant that has flowed in from the lowermost flat tube 41A reaches the uppermost flat tube 41D while being repeatedly distributed and merged in the first connecting tube 42 and the second connecting tube 43. For this reason, temperature unevenness of the high-pressure refrigerant can be eliminated, and uniform heat exchange can be performed, so that more efficient internal heat exchange can be performed. Further, since the high-pressure refrigerant passes through the plurality of high-pressure refrigerant passages 41a to 41d in the flat tubes 41A to 41D, the flow velocity is increased and the stirring of the high-pressure refrigerant in the first connection pipe 42 and the second connection pipe 43 is promoted. The

In addition, a continuous high-pressure refrigerant passage can be formed by simply winding a plurality of flat tubes 41A to 41D in parallel and individually connecting both ends thereof to the first connecting tube 42 and the second connecting tube 43. In addition, the flat tubes 41A to 41D are not subjected to complicated processing, and the flat tubes 41A to 41D, the first connection tube 42, and the second connection tube 43 can be easily attached to the outer peripheral surface of the gas-liquid separation unit 21. it can.

In addition, the high-pressure refrigerant flows through the flat tubes 41A to 41D in order from the lower side to the upper side outside the gas-liquid separation unit 21, while the gas-phase refrigerant separated by the gas-liquid separation unit 21 passes from the upper end of the inner cylinder 22b to the communication groove 22e. And then flows down to the second cap 24 side through a gas-phase refrigerant passage 22d formed between the outer cylinder 22a and the inner cylinder 22b. For this reason, a gaseous-phase refrigerant | coolant and a high pressure refrigerant | coolant become counterflow (counterflow), and can improve heat exchange efficiency more.

In the second embodiment, the case where the inlet 46a is formed in the first connecting pipe 42 has been described. However, the present invention is not limited to this, and the first connecting pipe 42 and the second connecting pipe 43 are connected. You may make it change right and left.
In the second embodiment, the case where four flat tubes 41A to 41D are used has been described. However, the present invention is not limited to this, and two, three, or even five or more flat tubes are used. You may make it wind. In this case, when an odd number of flat tubes are provided, the inlet 46a (or the outlet 46b) is formed in the first connecting pipe 42, and the outlet 46b (or the inlet 46a) is formed in the second connecting pipe 43. Therefore, the position of the partition plate is merely upside down, so that the first connecting pipe 42 and the second connecting pipe 43 can be used as a common part, and the first connecting pipe 42 and the second connecting pipe 43 are provided. The production cost can be reduced as compared with the case of manufacturing separately.

Furthermore, the 1st connection pipe 42 and the 2nd connection pipe 43 form the 1st connection pipe 42 and the 2nd connection pipe 43 by partitioning one cylindrical body in an axial direction instead of the case where it comprises separately. You can also. In this case, the first connecting pipe 42 and the second connecting pipe 43 can be manufactured with one part, and the number of parts can be reduced to reduce the production cost.
In the second embodiment, the case where the communication space of the first connection pipe 42 and the second connection pipe 43 is partitioned by the partition plates 44a to 44c has been described. However, the present invention is not limited to this. For the pipe 42, three cylindrical bodies having communication spaces 45a to 45c may be connected, and for the second connection pipe 43, two cylinders having

communication spaces

47a and 47b may be connected.

Moreover, although the said 1st and 2nd embodiment demonstrated the case where the bottom face of the inner cylinder 22b of the double pipe 22 was obstruct | occluded with the 2nd cap 24 and the liquid reservoir part 26 was formed, it is limited to this. Instead, the bottom surface of the inner cylinder 22b may be closed with a bottom plate that is a separate member from the second cap 24. In this case, the inner cylinder 22b does not need to protrude from the outer cylinder 22a, and the bottom surface of the inner cylinder 22b can be flush with the bottom surface of the outer cylinder 22a.

Moreover, although the said 1st and 2nd embodiment demonstrated the case where a some gaseous-phase refrigerant path was formed between the outer cylinder 22a and the inner cylinder 22b, a gaseous-phase refrigerant path is set to one or more arbitrary numbers. be able to. In this case, the partition wall 22c can be omitted, but in order to make the double tube 22 an extrusion-molded product, it is necessary to form one or more partition walls 22c. Furthermore, the double tube 22 may be configured by separately joining the outer tube 22a and the inner tube 22b by a joining means such as welding or brazing.

Moreover, although the said 1st and 2nd embodiment demonstrated the case where the accumulator 13 with an internal heat exchanger was comprised independently, it is not limited to this, The compressor 11, the heat radiator 12, and evaporation It can also be configured integrally with any of the containers 15. In short, it is sufficient that the vapor phase medium can be supplied from the accumulator 13 with the internal heat exchanger to the vapor phase medium suction portion of the compressor 11.
Moreover, although the said 1st and 2nd embodiment demonstrated the refrigerating cycle 1 applied to an air conditioner for motor vehicles, it is not limited to this, The refrigerating cycle used for a freezing showcase, a vending machine, etc. The present invention can also be applied to.

DESCRIPTION OF SYMBOLS 11 ... Compressor, 12 ... Radiator, 13 ... Accumulator with internal heat exchanger, 14 ... Expansion valve, 15 ... Evaporator, 21 ... Gas-liquid separation part, 22 ... Double pipe, 22a ... Outer cylinder, 22b ... Inside Cylinder, 22c ... partition wall, 22d ... gas phase refrigerant passage, 22e ... communication groove, 23 ... first cap, 23c ... inflow pipe, 24 ... second cap, 24c ... gas phase refrigerant reservoir, 24d ... discharge pipe, 26 DESCRIPTION OF SYMBOLS ... Liquid storage part, 27 ... Oil return groove, 31 ... Flat tube, 31a ... High pressure refrigerant path, 32 ... First connection pipe, 32a ... Inlet, 33 ... Second connection pipe, 33a ... Discharge port, 41A-41D Flat tubes, 41a to 41d ... high-pressure refrigerant passages, 42 ... first connection tubes, 43 ... second connection tubes, 44a to 44c ... partition plates, 45a to 45c ... communication spaces, 46a ... inlet ports, 46b ... discharge ports, 47a 47b ... Communication space

Claims

An accumulator arranged on the upstream side of a compressor provided in a circulation path for circulating a refrigerant in a refrigeration cycle, and gas-liquid separation of a gas-liquid two-phase refrigerant,
A gas-liquid separator having a double-pipe structure into which the gas-liquid two-phase refrigerant is introduced;
A flat tube wound around the outer periphery of the gas-liquid separator and through which a high-pressure refrigerant passes,
An accumulator with an internal heat exchanger, wherein internal heat exchange is performed between the gas-liquid separator and the flat tube.
The gas-liquid separation unit includes a double pipe including an inner cylinder that gas-liquid separates the gas-liquid two-phase refrigerant and an outer cylinder that forms a gas-phase refrigerant passage through which the separated gas-phase refrigerant passes. A first cap that is attached to one end of a pipe and guides the gas-liquid two-phase refrigerant into the inner cylinder, and is attached to the other end of the double pipe and discharges the gas-phase refrigerant in the gas-phase refrigerant passage to the outside. And a second cap that
In the double pipe, a plurality of gas-phase refrigerant passages are formed by a plurality of partition walls formed in the circumferential direction between the outer cylinder and the inner cylinder, and between the inner cylinder and the first cap. The accumulator with an internal heat exchanger according to claim 1, wherein a communication hole is formed to communicate the inner surface of the inner cylinder and the gas-phase refrigerant passage.
The flat tubes are opened at both ends in the winding direction, and a plurality of high-pressure refrigerant passages are formed in parallel while maintaining an interval in the axial direction of the double tube, and the plurality of high-pressure refrigerants at one end in the winding direction of the flat tubes A first connection pipe that communicates with the passage to form a high-pressure refrigerant flow path is coupled, and a second connection that communicates with the plurality of high-pressure refrigerant paths to form the high-pressure refrigerant flow path at the other end in the winding direction of the flat tube. The tube is connected, The accumulator with an internal heat exchanger according to claim 2 characterized by things.
The flat tubes are wound around the double tube in a plurality of rows, and the plurality of flat tubes have continuous refrigerant passages in which the high-pressure refrigerant flows in the reverse direction for each row through the first connection tube and the second connection tube. It forms, The accumulator with an internal heat exchanger of Claim 3 characterized by the above-mentioned.
The first connecting pipe and the second connecting pipe are connected so as to discharge the high-pressure refrigerant supplied from the second cap side from the first cap side through the flat pipe. The accumulator with an internal heat exchanger according to claim 3 or 4.
The first cap includes an inflow pipe that supplies a low-pressure refrigerant into the inner tube of the double pipe, and the second cap discharges the gas-phase refrigerant that passes through the gas-phase refrigerant passage of the double pipe to the outside. The accumulator with an internal heat exchanger according to any one of claims 2 to 5, further comprising a discharge pipe.
A compressor that sucks and compresses the refrigerant; a radiator that cools the refrigerant compressed by the compressor; a decompressor that decompresses the refrigerant cooled by the radiator; and evaporates the refrigerant decompressed by the decompressor The vaporizer and the gas-liquid two-phase refrigerant flowing out of the evaporator are separated into a vapor-phase refrigerant and a liquid-phase refrigerant, and the separated vapor-phase refrigerant is supplied to the compressor. An accumulator with an internal heat exchanger according to claim 1,
The gas-liquid two-phase refrigerant is supplied to the gas-liquid separator of the accumulator with an internal heat exchanger, and the separated gas-phase refrigerant is supplied to the compressor, and the high-pressure refrigerant flowing out from the radiator is supplied to the flat tube. A refrigeration cycle, characterized in that the high-pressure refrigerant supplied and discharged from the flat tube is supplied to the decompressor.